Stack smashing has become very different in the 21st century. Binary hardening
mechanisms used by default by all modern OSes make it nearly impossible to
exploit trivial buffer overflows. Since 1996, machines have evolved
significantly and you cannot even follow the original "Smashing the stack
[...]" tutorial by Aleph One on a modern computer.

Yet, there are other kinds of machines that are lacking all the binary
hardening we now take for granted. Because of that, they are ideal "target
practice" material for those who wish to learn about exploiting stack-based
buffer overflows or use them for causing real damage. Too bad these
machines "sit" on the edge of home and enterprise networks, often being the
only barrier between that the attackers need to overcome for a complete PWN.

In this talk I will demonstrate how we could smash the stack of two networking
devices from two different vendors (a wireless gateway, and a high-throughput
VPN concentrator), allowing for unauthenticated root access. I will also
present the vulnerability root-cause analysis and offer insights on why such
attacks are still viable in 2024.